The DocWiki should not contain any proprietary information. This restriction includes both Cisco-specific content and material from other companies.

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DocWiki should not contain any proprietary information. This restriction includes both Cisco-specific content and material from other companies.

The following content has been adapted from the ''Cisco Technical Documentation Style Guide'':

The following content has been adapted from the ''Cisco Technical Documentation Style Guide'':

Revision as of 16:19, 7 February 2008

DocWiki should not contain any proprietary information. This restriction includes both Cisco-specific content and material from other companies.

The following content has been adapted from the Cisco Technical Documentation Style Guide:

Do not use valid or potentially valid domain names or IP addresses, including examples, command output, and sample configurations. Inadvertent use of valid domain names or IP addresses can interfere with network operation, compromise network security and privacy, or conflict with intellectual property rights.

The following sections describe domain names and IP addresses that are safe to use:

Contents

Domain Names

RFC 2606 reserves the top-level domain .example for use in documentation or examples of code. The second-level domain names example.com, example.org, and example.net are also reserved for use as examples.

IP Addresses Reserved for Documentation

RFC 3330 assigns the address block 192.0.2.0/24 for use in documentation and examples of code.

Private IP Addresses

RFC 1918 provides a group of IP addresses that are never assigned publicly and are not routed through the public Internet. The same pool of addresses can be used within any private network (a network that does not communicate with the Internet or with other private networks, or communicates only through gateways that translate the IP address). You can use these IP address ranges for hosts that do not need access to the Internet.

Address Block

Starting Address

Ending Address

Approximate Number of Hosts

10.0.0.0/8

10.0.0.0

10.255.255.255

16,000,000

172.16.0.0/12

172.16.0.0

172.31.255.255

1,000,000

192.168.0.0/16

192.168.0.0

192.168.255.255

65,000

IP Multicast Addresses

RFC 1112 defines the address space for IP multicast addresses, which are generally safe to use in documentation because they cannot be reserved. IP multicast group addresses range from 224.0.0.0/8 to 239.0.0.0/8.

The Loopback (or Localhost) Address

By convention, most systems assign the IP address 127.0.0.1 and the name localhost to the loopback interface that allows a client and server on the same host to communicate with each other over TCP/IP. You can use the 127.0.0.1 localhost address in Cisco documentation.

The IPv6 Reserved Prefix

RFC 3849 sets aside the IPv6 address prefix 2001:0DB8::/32 for use in technical documentation. Addresses within this prefix are not routed through the public Internet.

To allow you to show complex network configurations, the IPv6 documentation prefix allows many different networks, subnetworks, and hosts. The following table shows three examples of networks within this prefix and a host address on each network. The table uses the following standard notation:

An IPv6 address consists of eight blocks, separated by colons.

Each block contains four hexadecimal numbers (16 bits).

Leading zeros within a block can be omitted.

A double colon (::) means that two or more consecutive blocks of 0000 have been omitted. This notation can be used only once per IPv6 address. The number of blocks omitted can be calculated from the number remaining.

A slash followed by a number (/n) means that the number of bits indicated do not change. For example, /48 means that the first 48 bits (three blocks) do not change.